Gas vortex-stabilized light source



Dec. 13, 1966 D. G- VAN ORNUM GAS VORTEX-STABILIZED LIGHT SOURCE 5 Sheets-Sheet 1 Original Filed June 20 1962 05455876 l A/V aP/VUM I-NVENTOR L BWN m 2 2 2 413 2 a .MQQM

Dec. 13, 1966 D. s. VAN ORNUM 3,292,028

GAS VORTEX-STABILIZED LIGHT SOURCE Original Filed June 20, 1962 3 Sheets-Sheet 2 5 I CVQQE/VT 500265 EQ{ W47Z:Q-QVT 82 62 maze //V- 72a PUMP I NVENTOR 05452-27 a MA ae/vu/v/ 1966 D. G. VAN ORNUM GAS VORTEX-STABILIZED LIGHT SOURCE 5 Sheets-Sheet 5 Original Filed June 20. 1962 United States Patent Ofil'lQQ 3,292,028 Patented Dec. 13, 1966 4 Claims. (Cl. 313-30 This invention relates to apparatus and methods for generating high intensity light by means of an electric arc. This application is a division of co-pending application Serial Number 203,760, filed June 20, 1962, now abandoned, for a Light Source and Methods, inventors Delbert G. Van Ornum, John W. Winzeler and Arthur C. Miller.

An object of the present invention is to provide an apparatus and method for stabilizing an electric arc by means of reflected radiation from such arc, thereby creating at a predetermined arc region a high-temperature highly-ionized volume through which the electron flow will tend to pass.

Another object is to provide a light source apparatus and method incorporating a high-current electric arc or spark which is stabilized by either gas-vortex stabilization or radiation stabilization, or by a combination thereof.

A further object is to provide a light source apparatus and method wherein the arc chamber contains gas under relatively high pressures.

A further object is to provide a light-generating apparatus and method wherein the wall of a substantially spherical chamber is made reflective in order to effect radiation stabilization of a high-current electric arc maintained at the center of such chamber, and wherein a relatively small window is adapted to extract light energy from the chamber.

An additional object is to provide a light-generating apparatus and method in which both gas-vortex stabilization and radiation stabilization are employed to stabilize a high-current electric arc or spark.

An additional object is to provide extremely eifective and efiicient light sources and methods adapted to be employed for a wide variety of purposes including spectroscopy ultraviolet sources for laser pumping, intelligence transmission, black body radiation, etc.

These and other objects and advantages of the invention will be more fully set forth in the following specification and claims, considered in connection with the attached drawings to which they relate.

In the drawings:

FIGURE 1 is a longitudinal central sectional view illustrating a first embodiment of the present light source; FIGURES 2 and 3 are transverse sectional views taken respectively on lines 2-2 and 33 of FIGURE 1, and illustrating means to introduce gas tangentially into the arc chamber;

FIGURE 4 is a central sectional view illustrating schematically an embodiment of the invention wherein 'the arc chamber is defined within a spherical wall coated by a spherical mirror surface and partially by an annular window region; and

FIGURES 7 and 8 are transverse sectional-views taken .respectively on lines 77 and '8-8 of FIGURE 6.

Referring first to the light source shown in FIGURES 1-3, the apparatus is seen to comprise an elongated transparent or light-transmissive tube 10 formed of quartz glass, fused silica or the like. Extended into opposite ends 'of tube 10 are electrode assemblies 11 and 12, such assemblies having opposedarcingportions 13 and 14, respectively. The arcing portions, which may comprise inserts of thoriated tungsten or the like, are arranged at the axis of the arc chamber 15 defined within tubing 10. It follows that -a high-current electric are or spark may be maintained between the arcing portions 13 and 14, such are being gas-vortex stabilized along the axis by means of gas which is introduced tangentially into arc chamber 15 as willbe described subsequently.

The electrode assembly 11 illustrated at the left in FIGURE 1 may comprise a generally cup-shaped copper body 17 having an elongated'tubular stem or center portion 18 which extends into the tubing 10, there being a suitable sealing sleeve 19 provided between portion 18 and tubing 10 to prevent leakage of gas from the arc chamber. Tubular portion 18 defines within it a coolant chamber 21 the outer end of which is closed by a plate or disc 22 which is suitably secured to the outer end of body 17. The innerend of coolant chamber 21 is closed by a generally conical electrode element 23 having the above-indicated arcing insert 13 mounted at the apex portion thereof. Suitable-means, including-sealing rings which prevent leakage of water or other coolant from chamber '21, are provided to associate plate 22 and electrode element 23 with opposite end portions of the tubular portion '18. Other suitable means, including a seal-mounting sleeve 24- and a bolted-on retaining ring 25, are provided to associate the wall of cup-shaped body 17 with the end portion of the transparent tubing 10.

A pipe or tube 27 is inserted longitudinally intothe coolant chamber 21 to introduce water therein at a point relatively adjacent the conical electrode element 23, such water then passing outwardly through the coolant chamber and through a discharge conduit or pipe 28. Other conduits or passages are formed through the tubular portion '18 of the copper body 17 in order to introduce gas tangentially into arc chamber 15. Referring to both FIGURES 1 and 2, three passages 30-32 are formed longitudinally through the tubular body portion 18 and corrimunicate respectively with pipes 33-35 leading to a suitable source 36 of gas under pressure. The passages 30-32 turn right-angled corners, as shown in FIGURE 2, so that they will enter the arc chamber 15 tangentially through the tangential passage portions 37-39. Such portions emerge from tube 18 at a beveled or frustoconical inner end portion 41 thereof and which is generally flush with the external surface 42 of the electrode element 23.

The electrode assembly 12, shown as the right in FIG- URE 1, comprises an elongated copper body 44 having a reduced-diameter tubular extension 45 which is inserted into the transparent tube 10 as in the case of the portion 18 of electrode assembly 11. The relationship of copper body 44 and its extension 45 relative to quartz tube 10 is substantially the same as was described relative to the assembly 11. Thus, .a sealing sleeve 19a, seal-mounting sleeve 24a and retaining-ring 25a are provide At the inner end of the tubular extension 45 of body 44 is mounted a-generally conical electrode element 46 having a conical outer surface 47. Such surface is generally flush with the frustoconical surface 48 at the inner end of extension 45. Means are provided to feed gas through extension 45 into arc chamber 15, and may correspond exactly to the previously described means 30-39,

the tangential inlet passages being directed in the same direction as the inlet passages 37-39. Thus, three passages 50-52 are fed with gas from pipes 53-55 leading to a suitable gas source 56. The passages terminate in the tangential inlet portions 57-59.

It is pointed out that the cone angles of the electrode surfaces 42 and 47, and their cooperating frustoconical surfaces 41 and'48, correspond generally to each other. Such angles are onthe order of thirty to sixty degrees from the axis of the arc chamber 15. The cone angles should not be so large that a substantial amount of light generated by the electric are or spark (including the footpoints thereof) which passes between arcing portions 13 and 14 is prevented from radiating through the lighttransmissive wall means 10.

It is a feature of the light source that the interior surface of the quartz tube (which is a surface of revolution about the axis of chamber 15) is maintained clean and cool by the vortically-flowiug gas which is introduced into the arc chamber 15 as described above. Such gas is heated by the arc and then is discharged axially through the electrode element 46. The gas or plasma is then cooled and discharged into the ambient atmosphere, or is cooled and then recirculated to the gas source or sources 36 and '56. It is to be understood that the sources 36 and 56 may be combined, and that they may be eliminated and replaced by pump means communicating with the conduit means through which gas passes outwardly from are chamber 15.

The plasma generated in arc chamber 15 discharges through the arcing insert 14, which is tubular in shape, and then passes into a tubular stem portion 61 of the electrode element 46. Such stem is sealingly connected to an elongated metallic tubular conduit. 62 which extends through the end plate 63, the latter corresponding to the plate or disc 22 of electrode assembl 11. The end plate 63 is adapted to sealingly close the outer end of concentric outer and inner coolant chambers 65 and 65 which are separated by an elongated tubular baffle or divider element 66. Element 66 extends from the end plate 63 to a region relatively adjacent the interior surface of electrode 46, at which point communication is effected between the chambers 64 and 65 so that Water may flow in series therethrough.

Water is fed into the outer chamber 64 by means of a pipe 67, from whence it flows around the inner end of divider 66 to the inner chamber 65 and thence to a discharge pipe 68. In this manner, the electrode 46 and also the stem 61 and conduit 62 are effectively cooled. It is pointed out that the conduit 62 and associated coolant chambers may be of any desired length, in accordance with the degree to which it is desired to cool the plasma prior to discharging or recirculating it. An effective predetermined heat-exchanger action is thus achieved.

DESCRIPTION OF THE METHOD Embodiment of FIGURES l-3 In performing the method with the light source illustrated in FIGURES 1-3, the electrode assemblies 11 and 12 are adjusted axially of the transparent tube 10 until the arcing inserts 13 and 14 are spaced a predetermined desired distance from each other. Such distance is preferably between about 3 millimeters and about 20 millimeters. If the arc length (electrode spacing) is excessively short, much of the radiation from the arc footpoints is lost or ineffective. n the other hand, a long are or spark requires high voltages and is less susceptible to being radiation stabilized as will be described relative to FIGURES 4 and 5.

The gas sources 36 and 56, or the pumping means in systems wherein recirculation is employed, are then utilized to introduce gas through the various conduits, passages and tangential passage portions 37-39 (FIGURE 2) and 57-59 (FIGURE 3). Such gas may comprise, for example, argon, xenon, neon, krypton, helium, or mixtures thereof. The gas flows vortically in the arc chamber 15 and then discharges through the insert 14, stem 61 and conduit 62. The various factors are so selected that the gas pressure within arc chamber 15 is high, being preferably at least p.s.i. absolute. A preferred pressure is about 250 p.s.i. absolute or somewhat higher, since black-body radiation is then approached or achieved.

An electric arc or spark is then initiated between the inserts 13 and 14, through use of a current source 70 and associated leads 71 and 72 which are connected to the respective electrode assemblies '11 and 12. It is to be understood that such leads may be associated with the water conduits, so that they are water cooled. Furthermore, and very importantly, it is to be understood that the current source 70 may be adapted to supply direct current, single or multi-phase alternating current, compound direct and alternating current, or pulses of current. Thus, for example, source 70 may comprise a capacitor bank and appropriate triggering apparatus. Where source 70 is a DC. source, insert 14 is preferably positive and insert 13 negative.

In apparatus wherein source 70 is of the steady-state type, means are provided to initiate the are between the inserts 13 and 14. In the present apparatus, such means is illustrated to comprise an elongated electrode 73 surrounded by an insulating sleeve 74. The tip of the electrode 73 is disposed relatively adjacent insert 13 but out of contact therewith. To start the are between inserts 13 and 14, current source 70 is applied following which a pulse of high voltage is impressed between the electrode 73 and one of the electrode assemblies 11 and 12. A spark is thus generated therebetween, such spark ionizing the gap between inserts 13 and 14 and serving to initiate the main arc.

The current source 70 is caused to supply a large current, for example on the order of 300 amperes or more. The voltage between the inserts may be on the order of 20 to 60 volts, for example, depending on factors such as the gas pressure and the spacing between the inserts. The rate of the gas flow passing through the arc chamber 15 may be, for example, about one-quarter standard cubic foot per minute up to three or four standard cubic feet per minute, such rate being given for argon gas.

The arc is gas-vortex stabilized and constricted between the inserts 13 and 14, so that it extends along a straightline path coincident with the axis of chamber 15. Furthermore, the vortically-flowing gas efficiently cleans and cools the interior wall of the glass tube 10, it being pointed out that any impurities or contaminants removed from the electrodes are discharged through the insert 14 instead of contacting the transparent tube.

The plasma generated by the arc is efliciently cooled during its passage through the long water-cooled conduit 62, such conduit being sufliciently long (for example a number of feet) to achieve the desired degree of cool ing. The gas may then be discharged to the ambient atmosphere or may be recirculated by suitable pump means to the inlet pipes 33-35 and 53-55. Suitable filter means may be incorporated in such recirculation means in order to remove any contaminants prior to re-introduction of the gas-into arc chamber 15.

Embodiment of FIGURES 4 and 5 FIGURES 4 and 5 illustrate an embodiment which is adapted to contain gas at high pressures, for example many hundreds of pounds per square inch, without requiring an excessively thick and thus inefiicient window means. Furthermore, and very importantly, the embodiment of FIGURES 4 and 5 utilizes what is believed to be the new principle of radiation stabilization of an electric arc, preferably in conjunction With gas-vortex stabilization thereof.

The apparatus comprises wall means 76 to define a spherical cavity or chamber 77 having a highly reflective wall. Preferably, the wall means 76 is formed of metal (for example of two bolted-together and sealingly-related metal halves, not shown), being provided on the interior (concave portion) thereof with a first-surface mirror coating 78 of vaporized aluminum or the like. Means are provided to cool the mirror coating 78, and may comprise chambers 79 and 80 through which water is passed continuously by conduit means 81 and 82.

First and second elongated electrode assemblies 84 and 85 are introduced into the cavity 77 through the poles thereof, being disposed axially of the chamber (along a line between the poles). The first such assembly may comprise a hollow metal tube through which water is passed continuously by means of conduits 86 and 87. Such tube has a beveled or conical inner end which preferably incorporates a thoriated tungsten insert (not shown) corresponding generally to the one 13 illustrated in FIGURE 1. The second such assembly 85 also comprises a hollow metal tube, preferably having an insert such as the one of 14 previously described, and adapted with a bafile or divider sleeve 88 for cooling by means of water conductors 89 and 90. A central conduit 91 is adapted to receive hot gas or plasma generated by the electric are or spark discharge which passes between the opposed arcing ends of the electrodes.

The external surfaces of assemblies 84 and 85 are highly polished and thus reflective, being preferably coated with vaporized aluminum. Suitable means, indicated as sleeves or bushings 92 and 93 formed of insulating material, are provided to insulate the electrodes from the metal wall means 76.

The gas which discharges through the central conduit 91, after cooling in the electrode 85 (or in other cooling and filter means), is passed to a pump 95 and thence to two gas inlet passages 96 and 97. Such passages are, as shown in FIGURE 5, oriented tangentially of the cavity, it being understood that the axis of the cavity is defined as the line between the poles and along which the electrodes 84 and 85 extend. The gas is thus caused to flow vortically about the electrodes to effect gas-vortex stabilization of the are or spark therebetween. Such gas also effects cooling and cleaning of the mirror coating 78. Additional tangential passages may be provided.

A window element 99 is located at the equator of cavity 77, being indicated as frustoconical in shape so as to resist being blown out by the high pressure within the chamber. The minor diameter of window 99 is slightly larger than the gap between the opposed tip or arcing portions of electrodes 84 and 85, such arcing portions being spaced equal distances on opposite sides of the equatorial plane of the cavity. Window 99 may be replaced by a suitable lens or lens system At a small region 100, diametrically opposite from window 99, the mirror forming the wall of cavity 77 is not concentric with the center of the cavity. Instead, such region 100 is adapted to focus at or somewhat outside of the window 99 as indicated by the phantom lines 101 and 102. Thus, the region 190, which has a radius of curvature substantially larger than that of the remainder of the wall of cavity 77, is adapted to form the reflected image of the arc or spark at the exterior surface of window 99 or at a point outside of such window.

From the above it will be understood that light is caused to emanate from cavity 77 in two ways and two ways only, namely by direct transmission from the arc or spark through window 99, and by reflected transmission from the are by means of the mirror element or region 100. Substantially all other light energy created by the arc is reflected back to the are as indicated by the various lines 103,

6 DESCRIPTION OF THE METHOD AND OF ADDITIONAL APPARATUS Embodiment of FIGURES 4-5 In performing the method of the embodiment of FIGURES 4 and 5, a suitable gas such as helium, argon, xenon, neon or krypton, is continuously circulated through the cavity 77 by means of pump 95. As previously described, such gas flows vortically about the polar axis along which the electrode assemblies 84 and ore oriented. The gas pressure should be high, such as hundreds of pounds per square inch absolute.

An electric are or spark is generated between the opposed tips of electrodes 84 and 85, the are being initiated 'by a suitable starting means (not shown) such as the one described relative to element 73 of the previous em bodiment. Such are is gas-vortex stabilized asdescribed heretofore, and is also radiation stabilized by means-of reflected radiation (for example, along the indicated lines 103) from the mirror surface 78.

Stated otherwise, the radiation emanating from the arc and striking the spherical mirror, surface 78. is reflected back to the arc, causing the temperature to be highest at and near the center of the cavity. Such temperature is much higher than would be the case in the absence of the mirror 78. Because of this extremely high temperature, the gas at the center of the cavity is highly ionized, approaching a black body at greater than 10,000 Kelvin. The existence of the highly-ionized gas volume at the center of the sphere stabilizes the are along the polar axis, since the electron flow passes through the zone of highest temperature and thus highest conductivity.

As previously described, the intense light energy is extracted from the cavity center by means of the mirror portion and also by direct radiation through window 99. Such window 99 may, as previously indicated, be shaped as a lens. The described radiation stabilization, preferably in combination with the gas-vortex stabiliza tion effected by the whirling .gas flow, is highly effective in stabilizing and constricting the are along the polar axis.- The whirling or vortical gas flow further serves to maintain the mirror surfaces and the surface of window '99 clean and relatively cool.

It is pointed out that the arc should :be kept relatively short so that a major portion thereof will be located at or near the exact center of cavity 77. The effectiveness of the radiation stabilization caused by mirror surface 78 is thus maximized.

The current source 7011 for supplying power to the electrodes, by means of leads 71a and 72a, may be the same as or similar to the one previously indicated. Thus, it may comp-rise a DC. or A.C. source, a pulse source, etc.

Particularly where the current source 7041 is a bank of low-inductance capacitors, it is desirable to perform triggering by moving the electrode assemblies 84 and 85' axially relative to each other. Thus, for example, electrode 84 may be axially movable by means of a suitable solenoid associated therewith. To initiate the high-current spark, the tip of electrode 84 is initially caused to be spaced sufliciently far from electrode 85 that charging of the capacitors 70a will not result in generation of the spark. The solenoid is then employed to move electrode 84 toward electrode '85 until the gap therebetween is so small that the spark will be initiated. In this manner, the capacitor bank is discharged without loss of energy in spark gaps external to chamber 77.

Additional stabilization of the arc or spark, in any embodiment of the invention, may be achieved magnetically by disposing a current-carrying coil coaxially therearound. For example, particularly where source 70a is a capacitor bank, the metal wall means 76 may be split at one point by an insulating sheet, not shown. Such insulating sheet is disposed in the same plane as the electrodes, and extends inwardly sufliciently far that its inner edge is flush with a 180 segment of mirror coating 78. A single-turn circuit is thus created through wall means 76, much as described in Waniek Patent 2,939,048, so that current will flow about the polar axis. Such singleturn circuit is caused to be in series with capacitor bank 70a and electrodes 84 and 85, for example by connecting leads 71a and 72a to the equatorial portions of wall means 78 adjacent opposite sides of the insulator. Discharge of the capacitor bank then generates the spark and also a spark-stabilizing magnetic field. The result is a combination of radiation stabilization, gas-vortex stabilization, and magnetic stabilization.

Particularly in instances wherein helium is employed as the gas, the described apparatus is useful as a highintensity ultraviolet source. Additionally, as previously indicated, the apparatus :may serve as a light source for spectroscopy, as the ultraviolet light source for laser pumping, and for numerous other purposes.

Embodiment of FIGURES 6-8 It is to be understood that the various principles described relative to the preceding embodiments may be combined in various ways in accordance with factors such as the angle or area through which it is desired to discharge light from the apparatus.

FIGURES 6-8 illustrate an embodiment wherein the portion shown as the left is identical to that shown in FIGURE 1, having been given in FIGURES 6 and 7 the same numbers applied to FIGURES 1 and 2. The right portion of the showing of FIGURE 6 is, except as will be specifically stated, generally the same as the right portion of FIGURE 1. Elements in FIGURE 6 which correspond to the right portion of FIGURE 1 have been given the same reference numerals except followed by the letter b in each instance.

The electrode portion 46b (having the arcing insert 14b therein) is shown as integral with the copper body 44b. Such electrode element and body are formed adjacent the base of the cone 46b as a generally hemispherical mirror surface 107 of vaporized aluminum or the like. The center of the surface 107 is located at the axis of chamber 15b and midway between the adjacent tips of arcing from source 36 (FIGURE 7) but also from a source 111.

Such source supplies gas to a tangential passage 112 (FIGURE 8) which connects to an inlet opening 113 on the mirror surface 107. Thus, the gas introduced from the source 111 aids in cooling and cleaning the mirror surface. It is to be understood that gas may be introduced at spaced points around the mirror.

The method relative to the embodiment of FIGURES 6-8 may be generally the same as previously described. The are or spark generated between inserts 13 and 14b is gas-vortex stabilized by light reflected thereto from mirror 107. The light is discharged about a 360 region through the trans-parent window means b.

The following is a summary of certain of the above, and other, important advantages which are achieved relative to vortex-stabilized or vortex and radiation-stabilized light sources constructed in accordance with various ones of the embodiments of the present invention, it being understood that a number of such advantages apply also to sources which are radiation stabilized only:

(2) The vortex fixes the arc plasma diameter, and precisely locates the arc column.

(3) The source will operate in any attitude and in any environment, such as in sea water or in a vacuum.

(4) The source will operate at very large power levels, and through a wide range of power levels.

(5) Spectral energy distribution may be varied by employing different gases or mixtures thereof.

As a specific example, relative to the first embodiment of the invention, operated on D.C. power, the arc plasma was 10 millimeters long by 3 millimeters in diameter. The input power was 24.8 kilowatts at a chamber pressure of 17 atmospheres, so that the plasma temperature was approximately 7,000 degrees Kelvin. The useable radiation solid angle was 10 steradians, and a luminuous output of 42,200 candles was generated. The average brightness was 140,000 candles per square centimeter, the luminous efficiency being 17 lumens per watt. The total radiant output, luminous and non-luminous, was 7.68 kilowatts radiant flux, making the over-all efiiciency 30.9%. The ultraviolet output (200 to 400 millimicrons) was 2.6 kilowatts radiant flux.

Various embodiments of the present invention, in addition to What has been illustrated and described in detail, may be employed without departing from the scope of the accompanying claims.

I claim:

1. Apparatus for generating and stabilizing an electric arc, comprising means to define an arc chamber, means to form in said chamber a concave highly-reflective surface which is at least a major portion of a sphere, means to generate at the center of said reflective surface an electric are adapted to radiate substantial quantities of radiant energy to said surface for reflection back to said are, said are being stabilized due to the elevation of temperature at said center caused by said reflected radiant energy, and means to effect flow of gas in said chamber vortically about said are to aid in stabilizing said are and to cool and clean said reflective surface.

2. A radiation-stabilized high-intensity light source, which comprises wall means to define a substantially spherical cavity adapted to contain gas under high pressures, first and second electrodes extended into said cavity along the polar axis thereof, at least one of said electrodes having an axial gas-discharge passage therethrough communicating with the arcing portion thereof, the arcing portions of said electrodes being disposed on opposite sides of the equatorial plane of said cavity along said polar axis in order to maintain along said polar axis a high-current electric are or discharge, means to generate a high-current electric arc or discharge between said arcing portions, a relatively small pressure-resistant window provided in said wall means at the equatorial portion of said cavity to transmit light from said discharge, means to form a first mirror surface at the equatorial portion of said cavity diametrically opposite said window, said first mirror surface being adapted to reflect light from said discharge to and through said window, means to form a second mirror surface along substantially the entire cavity-defining surface of said wall means, said second mirror surface being adapted to reflect light from said discharge back to said discharge for radiation stabilization thereof, and means to introduce gas tangentially into said cavity for vortical flow about said polar axis, said vortical gas flow serving to efiect cooling and cleaning of said mirror surfaces and said window and also to effect gas-vortex stabilization of said are or discharge, said gas discharging through said passage in said one electrode.

3. The invention as claimed in claim 2, in which means are provided to cool said gas discharging from said cavity and to effect recirculation of said gas back to said cavity for vortical flow therein.

4. A high-intensity light source, comprising light-transmissive wall means to define an arc chamber, said wall means forming a surface of revolution about a central axis, first and second electrode means extended axially into said chamber to maintain along said axis a high-current electric are, said electrode means being shaped to permit direct transmission of light from said are through said wall means, generally hemispherical reflector means provided in said chamber to reflect light from said are back to said are for radiation stabilization thereof, said reflector means also forming a surface of revolution about said axis, said reflector means encompassing one of said electrode means and being coaxial with said axis, and means to effect flow of gas in said are chamber vortically about said axis and thereafter to discharge said gas axially through one of said electrode means for gas-vortex stabilization of said are.

References Cited by the Examiner UNITED STATES PATENTS Evans 313-1l3 Ryland 8824 Lorenz 313-110 Prout et a1 313-231 Gage 313231.5

Rosener et a1. 315-111 DAVID I GALVIN, Primary Examiner. 

1. APPARATUS FOR GENERATING AND STABILIZING AN ELECTRIIC ARC, COMPRISING MEANS TO DEFINE AN ARC CHAMBER, MEANS TO FORM IN SAID CHAMBER A CONCAVE HIGHLY-REFLECTIVE SURFACE WHICH IS AT LEAST A MAJOR PORTION OF A SPHERE, MEANS TO GENERATE AT THE CENTER OF SAID REFLECTIVE SURFACE AN ELECTRIC CAR ADAPTED TO RADIATE SUBSTANTIAL QUANTITIES OF RADIANT ENERGY TO SAID SURFACE FOR REFLECTION BACK TO SAID ARC, SAID ARC BEING STABILIZED DUE TO THE ELEVATION OF TEMPERATURE AT SAID CENTER CAUSED BY SAID REFLECTED RADIANT ENERGY, AND MEANS TO EFFECT FLOW GAS IN SAID CHAMBER VORTICALLY ABOUT SAID ARC TO AID IN STABILIZING SAID ARC AND TO COOL AND CLEAN AND REFLECTIVE SURFACE. 